Repair guide

Replace Dreamcast VMU batteries

A VMU uses two coin cells that drain even when the unit sleeps, so a flat pair is the usual cause of a dead VMU.

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Battery · Easy · about 10 minutes. Worth doing. Reports say this fix helps on many machines.

You are in the right place if: The VMU screen is blank, the clock resets, or it loses its settings when removed from the controller.

Before you start

Do not mix old and new cells.
Rechargeable LiPo conversions involve opening the VMU and soldering. ConsoleMods covers this, but it is an advanced mod.

Parts you may need

CR2032 battery two-pack. VMU needs two Amazon · eBay

Tools

Small screwdriver. battery door if screwed Amazon · eBay
Isopropyl alcohol and swab. clean contacts Amazon · eBay

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Step by step

Remove the VMU Pull it from the controller or console.
Open the battery door Flip it over and open the cover on the back.
Note orientation Check which way the cells face before removing them.
Replace both cells Fit two fresh CR2032 batteries. Replace both at the same time.
Clean contacts if needed If it still does not wake up, wipe the battery contacts with an isopropyl alcohol swab.
Reinstall and test Set the clock, plug it into a controller and confirm the screen and saves work.

Tips, tales and maybes

Found in write-ups and forum threads. These are other people's reports, not tested by us.

Tip (Medium confidence). ConsoleMods notes a VMU uses two CR2032 cells that constantly drain even in sleep mode. Source

Guides we used

We wrote the steps in our own words from these. They have the photos and the full detail, so please read them and support their authors.

Dreamcast Rechargeable VMU Battery Mod (Wiki) by ConsoleMods Wiki. Notes that a VMU takes two CR2032 cells and covers a LiPo conversion.

Boards and models vary, so check what is in front of you. A repair can involve hot tools, chemicals and, on some machines, dangerous voltages. You do it at your own risk.